docs: def _handle_one(self):
          """
          Handle one read/write cycle.
          """
          ready_to_read, ready_to_write, in_error = select.select(
              [self.request], [self.request], [self.request], 0.1)
  
          if in_error:
              raise self.Disconnect()
  
          # Write any commands to the client
          while self.send_queue and ready_to_write:
              msg = self.send_queue.pop(0)
              self._send(msg)
  
          # See if the client has any commands for us.
          if ready_to_read:
              self._handle_incoming()